Azorella compacta Organic Extracts Exacerbate Metabolic Dysfunction-Associated Fatty Liver Disease in Mice Fed a High-Fat Diet.

Azorella compacta (A. compacta) is a shrub of the Andean Altiplano of Bolivia, Chile and Peru, consumed by local communities as a traditional medicine for several maladies such as diabetes, hepatic and inflammatory diseases. A. compacta is rich in mulinane- and azorellane-type diterpenoids. For two of these, acute hypoglycemic effects have been described, but the impact of A. compacta diterpenoids on fatty liver disease has not been investigated. Therefore, A. compacta organic fractions were prepared using petroleum ether, dichloromethane and methanol. Their content was characterized by UHPLC/MS, revealing the presence of ten diterpenoids, mainly mulinic acid, azorellanol and mulin-11,13-diene. Next, mice fed with a high-fat diet (HFD), a model of metabolic dysfunction-associated fatty liver disease (MAFLD), received one of the fractions in drinking water for two weeks. After this treatment, hepatic parameters were evaluated. The A. compacta fractions did not reduce hyperglycemia or body weight in the HFD-fed mice but increased the serum levels of hepatic transaminases (AST and ALT), reduced albumin and increased bilirubin, indicating hepatic damage, while histopathological alterations such as steatosis, inflammation and necrosis generated by the HFD were, overall, not ameliorated by the fractions. These results suggest that organic A. compacta extracts may generate hepatic complications in patients with MAFLD.

Talaroacids A-D and Talaromarane A, Diterpenoids with Anti-Inflammatory Activities from Mangrove Endophytic Fungus Talaromyces sp. JNQQJ-4.

Five new diterpenes including four diterpenes with 1,2,3,4,4a,5,6,8a-octalin skeleton talaroacids A-D (1-4) and an isopimarane diterpenoid talaromarane A (5) were isolated from the mangrove endophytic fungus Talaromyces sp. JNQQJ-4. Their structures and absolute configurations were determined by analysis of high-resolution electrospray ionization mass spectroscopy (HRESIMS), 1D/2D Nuclear Magnetic Resonance (NMR) spectra, single-crystal X-ray diffraction, quantum chemical calculation, and electronic circular dichroism (ECD). Talaromarane A (5) contains a rare 2-oxabicyclo [3.2.1] octan moiety in isopimarane diterpenoids. In bioassays, compounds 1, 2, 4, and 5 displayed significant anti-inflammatory activities with the IC50 value from 4.59 to 21.60 µM.

Diterpenoids from the Aerial Parts of Isodon serra with Selective Cytotoxic Activity.

Four new diterpenoids, isodosins A-D (1-4), together with nine known compounds (5-13) were isolated and identified from the aerial parts of Isodon serra (Maxim.) Hara. The structures of the new diterpenoids were elucidated based on the analysis of HR-ESI-MS data, 1D/2D-NMR-spectroscopic data, and electronic circular dichroism (ECD) calculations. Cytotoxicities of compounds 2, 3, 5, 6, and 9 against the HepG2 and H1975 cell lines were evaluated with the MTT assay. As a result, compounds 2, 3, and 6 revealed higher levels of cytotoxicity against HepG2 cells than against H1975 cells. Moreover, compund 6 demonstrated the most efficacy in inhibiting the proliferation of HepG2 cells, with an IC50 value of 41.13 ± 3.49 µM. This effect was achieved by inducing apoptosis in a dose-dependent manner. Furthermore, the relationships between the structures and activities of these compounds are briefly discussed.

Labdane-type diterpenoids with cytotoxic and anti-inflammatory activities from the aerial parts of Hypoestes purpurea (L.) R. Br.

Two new ent-labdane diterpenoids, hypoestesins A-B (1-2) and five new labdane diterpenoids, hypopurolides H-L (3-7), were isolated from the aerial parts of Hypoestes purpurea. All of the structures were fully determined based on extensive analysis of 1H, 13C, 2D NMR, and HRESIMS data. The absolute configurations of 1-3 was established through comparing the experimental and calculated ECD curves and the structure of 5 was confirmed by single crystal X-ray diffraction experiment. Compounds 5-7 were unusual C23 labdane diterpenoids having a γ-acetonyl-α, ß-unsaturated γ-lactone unit and each assigned as C-15 epimeric mixture. Furthermore, cytotoxic and anti-inflammatory activities of 3-7 were evaluated. The results showed that 3 had remarkable cytotoxic activity against HL-60, A549, SMMC-7721, MDA-MB-231, and SW480 cancer cell lines with IC50 values ranging from 2.35 to 17.06 µM. Compound 4 showed moderate cytotoxic activity against HL-60 and SMMC-7721 cancer cell lines with IC50 values of 15.12 ± 0.53 and 12.92 ± 0.60 µM, respectively. Furthermore, compound 4 was also found to exhibit inhibitory activity against NO production in RAW 264.7 macrophages with IC50 values of 23.56 ± 0.99 µM, compared to the positive control L-NMMA with an IC50 value of 41.11 ± 1.34 µM.

Abietane diterpenoids from Isodon amethystoides and their biological activities.

Seven undescribed abietane diterpenoids [abietamethinols A-G (1-7)] were isolated from the twigs and leaves of Isodon amethystoides. Their structures were elucidated on the basis of spectroscopic methods including 2D NMR, and they were further confirmed by X-ray crystallographic data. Lophanic acid was considered as the precursor of 1-7 in the biosynthesis pathway hypothesis. These compounds were evaluated for their cytotoxic, anti-bacterial and anti-AIV (avian influenza virus) activities. Compound 5 showed 42.9% inhibitory activity against the cancer cell line SMMC-7721 at the concentration of 40 µM, 3 and 4 could inhibit the bacterial growth of Streptococcus sobrinus by 55.3% and 63.2% at the concentrations of 148.6 and 141.9 µM, respectively, and 4 was demonstrated with antiviral activity against AIV with the inhibitory effect of 68.4% at 25 µM.

Structurally diverse diterpenoids and phenanthrene derivatives from the roots of Baliospermumsolanifolium.

Ten undescribed diterpenoids (1-10) and three undescribed phenanthrene derivatives (11-13), together with seven known compounds, were isolated from the roots of Baliospermum solanifolium. Their structures were determined by a combination of spectroscopic data analysis, electronic circular dichroism calculations and single-crystal X-ray diffraction studies. Compounds 1-7 (baliosperoids A-G) represent the examples of 20-nor-ent-podocarpane class first discovered in nature. In particular, compound 7 possesses a unique 2,3-seco ring system incorporating γ-butanolide moiety. All isolates were assessed for their cytotoxic activities against HT-29, HCT-116, HCT-15, MCF-7, and A549 cell lines as well as their inhibitory effects on lipopolysaccharide-induced NO production in RAW264.7 cells. Compound 1, a 20-nor-ent-podocarpane-type diterpenoid possessing a Δ1,2 double bond, not only exhibited considerable proliferation inhibition against five human cancer cell lines, with IC50 values ranging from 4.13 to 23.45 µM, but also displayed the most potent inhibitory activity on NO production with IC50 value at the nanomolar level (0.63 ± 0.21 µM).

Diterpenoids with Antibacterial Activities from the Fungus Trichoderma harzianum.

A new fusicoccane diterpenoid, harziaderma A (1), two novel harziane diterpenoids, harzianones G and H (2 and 3), one revised harziane diterpenoid (4), and two known diterpenoids (5 and 6) were isolated from the fungus Trichoderma harzianum and established via NMR, HRESIMS, Mo2(OAc)4-induced circular dichroism (ICD) and electronic circular dichroism (ECD) calculations. It is worth noting that compound 1 represents the first instance of a fusicoccane-type diterpenoid derived from T. harzianum. The structure of furanharzianone B was revised to 4 via careful spectroscopic analyses. Additionally, compounds 2 and 5 could suppress the overall growth of the foodborne bacterial pathogen Bacillus cereus. Compound 4 showed a moderate suppressive impact on NO generation in lipopolysaccharide (LPS)-treated RAW 264.7 cells. The discoveries from the current study not only expanded the structural variety of diterpenoids isolated from T. harzianum but also laid a robust foundation for the development of harziane diterpenoids as anti-foodborne pathogen agents.

Abietane-type diterpenoids: Insights into structural diversity and therapeutic potential.

The abietane-type diterpenoids are among the most significant diterpene subsets found in hundreds of plant species belonging to various families. Among which, the members of the genus Salvia and Euphorbia are rich in abietane diterpenoids. Because of the chemical diversity and notable bioactivities, such as anticancer, antiinflammatory, antimicrobial, and antioxidant activities, abietane-type diterpenoids are attractive. Herein, recent advances in the isolation and characterization of abietane-type diterpenoids from natural sources, as well as their biological activities, from 2015 up to 2024 are reviewed. During this time, over 300 abietane diterpenoids with diverse structures have been discovered.

New cytotoxic spatane diterpenoids from marine alga Stoechospermum marginatum.

Three new spatane diterpenoids (1-3) were isolated from the brown alga Stoechospermum marginatum together with three known compounds (4-6). The structures of these compounds were determined by the detailed NMR spectroscopic and Mass spectrometric analyses. All the isolated compounds were screened for their cytotoxic potentials against a panel of four human cancer cell lines, which include DU145 (Prostate), B16F10 (Melanoma), MDA MB-231 (Breast), and HeLa (Cervical) along with a normal cell line (HEK). The screening results indicated that compounds 1, 4 and 5 displayed significant activities against B16F10 [IC50, 6.21 ± 0.14, 5.88 ± 0.21, 5.31 ± 0.24 µM] and MDA MB-231 [9.25 ± 0.61, 4.59 ± 0.14, 4.19 ± 0.13 µM] cell lines, respectively. In view of their significant activity, these compounds 1, 4 and 5 were further taken up for detailed fluorescence assays, scratch assay and flow cytometry analysis, which revealed that they diminished proliferation and arrested cell cycle in the S phase and G2/M phase, which induced cell death by apoptosis. Overall, based on their considerable results, these compounds could serve as lead molecules in the development of anticancer drug candidates.

Three new antinociceptive diterpenoids from the fruits of Rhododendron molle.

Investigation of the fruits of Rhododendron molle G. Don led to the isolation of three new grayanane-type diterpenoids, rhodomolleins LIV-LVI (1-3). The structures and absolute configurations of new compounds were fully elucidated by spectroscopic analysis and single-crystal X-ray diffraction, including HRESIMS, 1 D and 2 D NMR data. Compounds 1-3 were evaluated for analgesic activities utilizing an acetic acid-induced writhing test in mice. Compound 1 showed a significant antinociceptive effect with writhe inhibition rates of 72.9% and 100% at doses of 6 mg/kg and 20 mg/kg in mice, respectively. The binding mode of 1 to N-ethylmaleimide-sensitive factor (NSF, PDB: 6IP2) was explored by molecular docking, indicating the presence of hydrogen bond interactions which account for its analgesic activity.

A green and simple method for enrichment of major diterpenoids from the buds of Wikstroemia chamaedaphne with macroporous resins and their activation of latent human immunodeficiency virus activity.

In this study, a green and efficient enrichment method for the four majors active diterpenoid components: pimelotide C, pimelotide A, simplexin, and 6α,7α-epoxy-5ß-hydroxy-12-deoxyphorbol-13-decanoate in the buds of Wikstroemia chamaedaphne was established using macroporous resin chromatography. The adsorption and desorption rates of seven macroporous resins were compared using static tests. The D101 macroporous resin exhibited the best performance. Static and dynamic adsorption tests were performed to determine the enrichment and purification of important bioactive diterpenoids in the buds of W. chamaedaphne. Diterpenoid extracts were obtained by using D101 macroporous resin from the crude extracts of W. chamaedaphne. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated that most of the diterpenoids were enriched in diterpenoid extracts. These results confirmed that diterpenoids in the buds of W. chamaedaphne could be enriched using macroporous resin technology, and the enriched diterpenoid extracts showed more efficient activation of the latent human immunodeficiency virus. This study provides a novel strategy for discovering efficient and low-toxicity latency-reversing agents and a potential basis for the comprehensive development and clinical application of the buds of W. chamaedaphne.

[Correlation between intestinal toxicity and composition changes of toxic parts from Euphorbia ebracteolata before and after Terminalia chebula soup processing].

This study aims to explore the correlation between intestinal toxicity and composition changes of Euphorbia ebracteolata before and after Terminalia chebula soup(TCS) processing. Intragastric administration was performed on the whole animal model. By using fecal water content, inflammatory causes, and pathological damage of different parts of the intestinal tract of mice as indexes, the differences in intestinal toxicity of dichloromethane extraction of raw E. ebracteolata(REDE), dichloromethane extraction of TCS, and dichloromethane extraction of E. ebracteolata after simulated TCS processing(STREDE) were compared, so as to investigate the effect of TCS processing on the intestinal toxicity of E. ebracteolata. At the same time, the component databases of E. ebracteolata and T. chebula were constructed, and the composition changes of diterpenoids, tannins, and phenolic acids in the three extracted parts were analyzed by HPLC-TOF-MS. HPLC was used to compare the content of four diterpenoids including ent-11α-hydroxyabicta-8(14), 13(15)-dien-16, 12-olide(HAO), jolkinolide B(JNB), fischeria A(FA), and jolkinolide E(JNE) in the E. ebracteolata before and after processing and the residue of container wall after processing, so as to investigate the effect of TCS processing on the content and structure of the diterpenoids. The results showed that the REDE group could significantly increase the fecal water content and the release levels of TNF-α and IL-1ß from each intestinal segment, and intestinal tissue damage was accompanied by significant infiltration of inflammatory cells. However, compared with the REDE group, the intestinal tissue damage in the STREDE group was alleviated, and the infiltration of inflammatory cells decreased. The intestinal toxicity significantly decreased. Mass spectrometry analysis showed that there was no significant difference in the content of diterpenoids of REDE before and after simulated TCS processing, but a large number of tannins and phenolic acids were added. The results of HPLC showed that the content of four diterpenoids of E. ebracteo-lata decreased to varying degrees after TCS processing, ranging from-0.35% to-19.74%, and the decreased part mainly remained in the container wall, indicating that the structure of toxic diterpenoids of E. ebracteolata was not changed after TCS processing. The antagonistic effect of tannic and phenolic acids in the TCS may be the main reason for the reduced intestinal toxicity of E. ebracteolata after TCS processing. The TCS processing for E. ebracteolata is scientific.

Abietane diterpenoids from Caryopteris incana (Thunb.) Miq. And their HIF-2α inhibitory activities in vitro.

Eleven previously undescribed abietane-type diterpenoids, named caryopincanoids A-K (1-11), together with five known compounds, were isolated from the EtOH extract of the aerial parts of Caryopteris incana (Thunb.) Miq. Their structures were elucidated on the basis of comprehensive spectroscopic data, NMR calculations, and ECD calculations. The inhibitory activities of all compounds against HIF-2α gene expression in 786-O cells were tested by luciferase assay. Compounds 7, 9, 15, and 16 showed significant inhibitory effects with IC50 values ranging from 12.73 to 23.80 µM. The preliminary structure-activity relationship of these compounds was also discussed.

Glechomenes A-G, diterpenoids with anti-inflammatory activities from the aerial part of Glechoma longituba.

Ten diterpenoids including six unreported abietane-type diterpenoids Glecholmenes A-F (1-6) and an undescribed labdane-type diterpenoid Glecholmene G (9), together with three known diterpenoids (7,8,10), were firstly isolated from the aerial part of G. longituba. Their structures were established mainly by nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) methods. Electronic circular dichroism (ECD) calculations and X-ray crystallographic analyses were used for the determination of their absolute configurations. The anti-inflammatory activity of all compounds was evaluated using the classical LPS-induced NO release model in RAW264.7 cells. Compound 2 displayed significant anti-inflammatory activities with IC50 values of 29.08 ± 1.40 µM (Aminoguanidine hydrochloride as the positive control, IC50 = 21.84 ± 0.48 µM).

Characteristic cembrane-type diterpenoids with nitric oxide inhibitory activity from the gum resin of Boswellia carterii Birdw.

Five new characteristic cembrane-type diterpenoids (olibacartiols A-E, 1-5) were acquired from the gum resin of Boswellia carterii. The structures of these diterpenoids were characterized by detailed spectroscopic analysis, and compounds 1-3 were unambiguously confirmed by single-crystal X-ray diffraction experiments. The anti-inflammatory activities of the isolated compounds were evaluated using LPS-induced BV2 cell model and compounds 2-5 showed moderate NO inhibitory effects with IC50 values of 8.84 ± 1.02, 9.82 ± 1.95, 9.75 ± 2.24, and 7.39 ± 1.24 µM, respectively.

Six new diterpenoids with anti-inflammatory and cytotoxic activity from Isodon serra.

Diterpenoids occupy an important slot of the natural products diversity space with wide ranges of bioactivities and complex structures, providing potential applications for the development of therapeutics. In this study, we reported four new abietane-type diterpenoids viroxocin B-E (1-4), a new totarane-type diterpenoid viroxocin F (5), and a new sempervirane-type diterpenoid viroxocin G (6) along with four known compounds (7-10), isolated and identified from a widely used Traditional Chinese Medicine, Isodon serra (I. serra). Their structures were established by spectroscopic data analysis, experimental and calculated electronic circular dichroism (ECD) data, as well as X-ray diffraction analysis. Compounds 2, 5, 7, 8 and 10 exhibited promising anti-inflammatory activities in lipopolysaccharide (LPS)-induced RAW 267.4 cells, and their inhibition rates on NO production were more than 60% at 10 µM. Compound 7 showed cytotoxicity against human renal cell carcinoma 769P at 20 µM, the inhibition rate was 52.66%.

Diterpenoids from Acanthopanacis Cortex and their anti-inflammatory activity studies.

Acanthopanacis Cortex (A.-C) with a long history of more than1000 years, has been used to treat rheumatism effectively. Nineteen diterpenoids have been isolated from A.-C, including six new compounds (1-6). Among them, compounds 7, 9-11, 13, and 17 were discovered from A.-C for the first time. The structures of 1-6 were determined by analyzing their NMR data and comparing their experimental and calculated electronic circular dichroism spectra. Moreover, the single-crystal X-ray diffraction data of 1, 2, 8, and 14 were provided. The anti-inflammatory activity of 1-5 and 7-18 on neutrophil elastase, cyclooxygenase-1 (COX-1), and cyclooxygenase-2 (COX-2) has been studied in vitro, and the results showed that 15 had almost no inhibitory effects on COX-1 at 200 µM but a significant activity against COX-2 with an IC50 of 0.73 ± 0.006 µΜ. It indicated that compound 15 can provide valuable information for the design of selective COX-2 inhibitors.

Crotonoids A-H, Labdane-Type Diterpenoids with Anti-Inflammatory Activity from Croton sublyratus.

Croton sublyratus (Euphorbiaceae) is a traditional medicinal plant used by the Thai populace to treat helminthic infections and dermatologic conditions. In present study, eight new labdane-type diterpenoids, crotonoids A-H (1-8) and one known analogue (9) were isolated from the aerial parts of C. sublyratus. Compounds 6 and 7 belong to the rare class of 14,15-dinor-labdane diterpenoids. Compound 8 exhibited a rare 14,15,17-trinor-labdane skeleton. The structures of all these diterpenoids were elucidated by spectroscopic data analysis, electronic circular dichroism calculations, and single-crystal X-ray diffraction analysis. Compound 9 exhibited moderate anti-inflammatory activity via the inhibition of NO production in lipopolysaccharide-induced RAW 264.7 cells.

Abietane-Type Diterpenoids from the Arils of Torreya grandis.

A chemical investigation of the arils of Torreya grandis led to the isolation of seven abietane-type diterpenoids (compounds 1-7) including three previously undescribed compounds, one unreported natural product, and three known analogs. The structures of these compounds were determined by means of spectroscopy, single-crystal X-ray diffraction, and ECD spectra. An antibacterial activity assay showed that compounds 5 and 6 had significant inhibitory effects on methicillin-resistant Staphylococcus aureus, with MIC values of 100 µM. Moreover, compounds 1, 3, 4, and 7 exhibited anti-neuroinflammatory activity in LPS-stimulated BV-2 microglia cells, with the IC50 values ranging from 38.4 to 67.9 µM.

Discovery of new 13(17)-epoxymyrsinane diterpenes from aerial flowering parts of euphorbia spinidens Bornm. ex Prokh. with proapoptotic activities against human bladder cancer EJ138 cells.

Phytochemical analysis of aerial flowering parts of Euphorbia spinidens Bornm. ex Prokh. from Euphorbiaceae family (local name: Farfion-e-dandaneh-khari) led to the isolation of five diterpenes based on myrsinane backbone. Using HRESI-MS, 1D, and 2D NMR, they were identified as two previously unreported: 33,7,14,15(ß)-tetraacetyl-5(α)-butanoyl-13α(17)epoxy-8,10(18)-myrsinadiene (1), 7,14,15(ß)-triacetyl-3(ß),5(α)-dibutanoyl-13α(17)epoxy-8,10(18)-myrsinadiene (2), and three known diterpenes: 3,7,14,15(ß)-tetraacetyl-5(α)-propanoyl-13(17)-epoxy-8,10(18)-myrsinadiene (3), and 3,7,10,14,15(ß)-Pentaacetyl-5(α)-butanoyl-13,17-epoxy-8-myrsinene (4), 3,7,10,14,15(ß)-pentaacetyl-5(α)-propanoyl-13,17-epoxy-8-myrsinene (5). Compound 5 was previously reported in the roots of the same plant but without NMR data. Therefore, its mass pattern,1H-, and 13C-NMR data are reported. The cytotoxicity and proapoptotic properties of 1-3 were evaluated against EJ-138 bladder carcinoma cells through standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay for cytotoxicity screening and annexin V-FITC/PI apoptosis detection kit. In the cytotoxicity assay, the IC50 values found against EJ-138 were: (1) 41.6 ± 3.54 µM; (2) 38.4 ± 2.54 µM; (3) 57.3 ± 5.4 µM, whilst the IC50 value of doxorubicin was 1.7 ± 0.3 µM, respectively. In apoptosis assay, total apoptosis of compounds 1-3 at higher concentrations (100 µM) were 57.6 ± 3.54, 46.3 ± 2.82, and 57.2 ± 4.35%, respectively.